From DE 100 50 059 A1, a cylinder air charging control system is known that adjusts inlet and outlet valves relative to a demand torque. When using a turbocharger, it is therefore proposed that the control device for inlet and outlet valves is opened simultaneously to avoid the delay during a torque increase, so that with a positive pressure difference between the intake and exhaust sides a flushing of the intake air to the exhaust side takes place.
From DE 100 51 416 A1, a method for controlling an internal combustion engine is known, that has an electronically controlled intake and exhaust device. To achieve a rapid change in the air/fuel ratio in the individual cylinders, the exhaust control device is used to control the airflow from the intake manifold into the cylinder.
From DE 100 51 425 A1, an engine control system for a direct-injection engine with variable valve timing is known. With this method, the fresh air charge in the cylinder is controlled faster with the aid of a cam control than would be possible by manifold dynamics alone. The method also includes changing the air/fuel ratio in the cylinder and changing the control of the exhaust control device accordingly. To compensate for incorrect calculations, a manifold pressure sensor is provided that calculates a manifold pressure error from the deviation between the detected manifold pressure and the actual manifold pressure.
From EP 1 243 779 A2, a direct-injection internal combustion engine with a turbocharger for reducing the consumption, particularly under full load, is known, whereby residual gas is scavenged from the cylinder to avoid knocking. To do this, the inlet and exhaust valves are opened simultaneously.
The methods previously described have one common disadvantage in that because of the scavenging there is no direct relationship between the measured (and produced therefrom) air volume that flows into the cylinder and the air volume that actually remains in the cylinder. An attempt is made to solve this problem by taking account of the “absorption behavior” of the cylinder. By means of the absorption behavior, the fresh air volume flowing into the cylinder is, for example, applied in relation to the inlet manifold. Other operating variables can also be taken into account.